Improved process for disintegrating vegetable fibers



i UNITED STATES PATENT OFFICE. I 5

CHAS. HEATON, OF NEW YORK, N. Y.

Specification forming part of Letters Patent No. 49,l06, dated August 1,1865.

To all whom it may concern:

Be it known that 1, CHARLES HEATON, of the city, county, and State ofNew York, have invented a new method of treating vegetable fibrousmaterials for the purpose of separating the fibers from the gums andsilica of the same; and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to full y understand and use my invention.

It is well known that vegetable fibrous substances-such as hem'p, straw,cane, reed, bamboo, or flax-when used for the manufacture of paper-pulp,felt, or textile fabrics, require to be subjected to the action of heatand moisture for the purpose of separating, utilizing, and softening thefibers. Various methods for separating these fibers have been patented.I The application to the fibers of great heat in conjunction with alkalior other softening solutions is not new, nor is the application of greatheat in conjunction with an explosion for the purpose of separating thefibers new. In all the various processes as heretofore practiced it iscustomary to treat the fibrous substance with great heat for a longtime, varyingfrom three to ten hours.

In carrying out my improvement I have dis covered that great heat for along time is not necessary to the successful treatment of vegetablefibers, and also that the use of alkaline solutions is not necessary inconjunction with great heat.

I have also discovered that the proper and necessary amount of heat,(which varies with different materials,) once developed and applied tothe fibrous substances, produces the necessary change in them without along-continued application thereof. As soon as the fibrous substance isunder the influence of the necessary degree of heat the required effectis produced at once as well or better than if said substance is keptunder the continued influence of the same heat for a long time.

I have also discovered that the application of heat of less intensitythan the heat required will not produce the necessary effect, no matterhow long continued, so well as a higher degree of heatinstantaneouslyapplied. In short, I discover when the right degree of heatisapplied tothe ,saidfibrous substances],the Idesired change in the gums takes placealmost instantly.

I also discover that the application of alkaline solutions inconjunction with great heat is not only unnecessary, but prejudical,inasmuch as the color of the fibrous material treated is injured by suchcombination.

I have also discovered that, after the necessary heat has been appliedto the material treated, alkaline solutions applied cold answer a betterpurpose than when applied in conjunction with heat.

I have also discovered that, after a separate successive application ofheat and alkaline solution, a boiling of the fibrous substance in anopen vessel without pressure is sufficient for softening the materialand producing a clean, soft pulp, felt, or fiber.

My improvements are applicable to all vegetable fibrous substances, thetreatmentof one of which substances-namely, cane or bamboo- I will nowproceed to describe. In the reduction of the bamboo to pulp for themanufacture of paper, felt, &c., the condition of the raw cane orbamboo, whether green or dry, may make itnecessary to change thestrength of chemicals and to vary the degrees of heat applied.

My process is as follows: I take the dry bamboo or cane inconvenient-sized bundles and soak in water until the mass is saturated,usually from three to twelve hours. After soaking I place the mass in aboiler, retort, or other suitable receptacle, and apply heat through themedium of steam at a pressure of not less than fifty pounds per inch.(In some cases it is necessary to apply as great a pressure of steam asone hundred and eighty pounds per square inch, according to thecondition of the material to be treated.) Fire or a hot-blast as avehicle of heat, instead of steam,might be used if sufficient moisturewas present to pre vent carbonizin g the materials. I prefer to usesteam as the most convenient and easiest ap plied. After the heat hasbeen applied and the material within the retort or other vessel has beenbrought under the influence of the heat, as shown by a gage placed onthe vessel for that purpose,I out off the supply of heat by allowing thesteamepressuregradually to subside. As soon as .thetheatf has; been reduced, I remove from the retort or vessel the material under treatmentand place it in a solution of caustic alkali of the specific gravity of2 Baum, at atemperature of 90. The alkaline solution, as well as itsstrength and temperature, may vary according to the condition of thematerial treated. I leave the material in this alkaline solution untilit has become softened. when I remove it, having first strained oft asmuch of the liquid as possible. I now pass the fibrous mass through aseries of rollers or submit it to other mechanical pressure for thepurpose of effecting a separation or a partial separation of the gumsand silica, which have become softened by the preceding treatment. Inpassing it through rollers I cause the material to be heated or dried bymaking the rollers hot by circulating steam through them. After thematerial has passed through the rollers, as described, the gums whichpreviously surrounded the fibers in a pasty or sticky condition havebeen mashed or flattened out so as no, longer to surround, but simply toadhere to, the fibers. The action of the rollers is found not to injurethe fiber, owing to the soft and yielding nature of the gums. Therollers being hot, the material, after passing through the rollers,readily and rapidly dries, whenthe gums become brittle and can bereadily shaken away from the fibers or beaten out in a willow or otherequivalent device. I now take the fiber, which by the above-describedprocess has become nearly or quite free from gums, and place it in aboiler or other receptacle, with a weak solution of alkali or othersolvent, and boil the mass for the purpose of softening the material andremoving any small portion of gum which may yet adhere to it, as well asto prepare it for bleaching. After being washed the mass is fit for useas pulp for the manufacture of paper, felt, or other fabric.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

The process herein described of treating vegetablefiber by subjectingitfor a short time to a high degree of heat without the'presence' ofalkali, and afterward immersing it in an alkaline solution at a lowertemperature. 1

CHAS. HEATON. Witnesses:

M. M. LIVINGSTON, U. L. TOPLIFF.

